There are several kinds of damper assemblies used in cupboard doors (sliding doors), dampers in a general damper assembly for a sliding door are used in relative left and right sides, and therefore the assembly requirement thereof is rigid; and while usually the damper assembly has only one damper and thus has limited damping force. Under the aforementioned prior art, if there is need to enhance damping force, two dampers for a damper assembly in both left and right sides may be required. Accordingly, pulling sheets would be needed to being arranged respectively with the tracks of dampers. As such, the whole structure would get complicated, bringing about higher assembly requirements.
In order to overcome the abovementioned defects, applicant of the present invention researched an upper wheel assembly with double dampers for the cupboard door and have a patent (patent No. 201320065103.7) on it, wherein two dampers in parallel are assembled in a cover of the upper wheel assembly with double dampers for cupboard door, and a pulling unit is assembled to a common fore-head of the two dampers which can pull or push both dampers simultaneously, so as to achieve the “stretch” and damping effect with cooperation of other units. For assembling, fixing the upper wheel assembly with double dampers on upper end of the door leaf, and fixing a pulling unit upside-down in the upper track by screw, and plugging a sliding pillar of the pulling unit into a circular arc groove of a damper sliding sheet of the upper wheel assembly with double dampers, in order to pull and push the damper sliding sheet.
However, with applying of the above-mentioned patented technology, the applicant found a problem to be solved that the door leaf jumps at the time of being open and closed because of accelerated velocity. In addition, problem of assembly of the pulling unit also needs to be solved, because assembly of the pulling unit into the upper track is not firm enough that the pulling unit is prone to drop when the door is pulled and pushed for much times. Moreover, the pulling pillar should be long enough to plug into the circular arc groove of the damper sliding sheet, while in fact it is not long enough as it is fixed on a base of the pulling unit which is assembled in the upper track, and it thus is prone to fall off the circular arc groove, and therefore the problem about the effective length of the pulling pillar of the pulling unit needs to be solved.
For the above, it is necessary to improve the above-mentioned technology.